EXPANDABLE DOWNHOLE TUBING

摘要

The present invention relates to portions of casing that are inserted into a wellbore. The casing portions are provided with a protected portion in which a friction and/or sealing material can be located. In certain embodiments, the protected portion is provided by first and second annular shoulders that are spaced-apart axially along the length of the casing. The friction and/or sealing material is typically located on an outer surface of the casing between the annular shoulders. There is also provided a casing portion that has annular shoulders provided at either end of the casing portion, with mea ns to connect successive casing portions located on these shoulders. The casing portion in this embodiment is provided with a friction and/or sealing materi al in a recessed portion of the casing portion.